Emma lost her savior status the moment she kissed hook. Untill then she was a savior. She saved everyone from cora, she saved the town from the diamond she saved Regina from the wraith, hooks ship from the mermaids etc. But the moment she kissed hook, all she became was a whiner. Im the savior! I never get a day off! Meanwhile, Regina saved everyone. Emma was useless. Rumple saved everyone. Emma was useless. Regina saved everyone again and again, and Emma was nothing but a whining toddler.
That is why Rumple was so disappointed when she did not choose to send her powers to the hat. She was very powerful, but did nothing with her powers because she was hook’s girl. If she had the sense to give up her powers, hook might have broken up with her, as the price of losing her magic i guess maybe he only wanted her because of her powers, but she woukd become an ordinary person.
Because she didnt so this, because she didnt let the hat suck out her powers, she turned to darkness. Because Power currupts, weather its light or dark power, it currupts. Gold was hoping she would choose not to have power. As the true hero he thought she was.
He created a savior. Hook distroyed the savior. Good thing he had a back up plan for a savior. Regina.